The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Forum Software Upgrade coming soon...
by HotLine1
01/17/17 03:23 PM
Would ELV branch circuits be a good idea?
by gfretwell
01/17/17 01:26 PM
Why cables look like they do
by Texas_Ranger
01/17/17 12:33 PM
Re: Fabricating Guards out of Lexan?
by ghost307
01/17/17 11:21 AM
100% breakers?
by Texas_Ranger
01/16/17 06:13 AM
New in the Gallery:
Desk-mounted "power-board"
Shout Box

Top Posters (30 Days)
HotLine1 20
Webmaster 15
Trumpy 12
ghost307 12
gfretwell 11
Who's Online
2 registered (HotLine1, frank), 0 Guests and 69 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#101937 - 03/05/04 06:40 PM heat tape
bill woods Offline
Member

Registered: 11/21/01
Posts: 45
I am troubleshooting some heat tape in some eaves troughing and downspouts. The breaker keeps tripping. The tape works intermittently. It is 8W per ft 240V tape.
I can't find the fault. Anyone have experience with this stuff?

Top
2017 / 2014 NEC & Related Books and Study Guides
#101938 - 03/05/04 06:45 PM Re: heat tape
crash Offline
Member

Registered: 10/21/03
Posts: 130
Loc: Calgary Canada
Is it the GFCI that keeps tripping, or is it the o/c keeps tripping?

Top
#101939 - 03/05/04 06:46 PM Re: heat tape
Trumpy Offline


Member

Registered: 07/05/02
Posts: 8552
Loc: SI,New Zealand
There isn't a chance that the tape has been cut?.
I've seen this before with one of the wires being cut right through and only making intermittent contact.
Sounds rather dangerous actually, especially around snow!.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

Top
#101940 - 03/06/04 07:02 AM Re: heat tape
bill woods Offline
Member

Registered: 11/21/01
Posts: 45
There is actually two systems I'm dealing with. One is GFCI'd and the other is not. Both systems are tripping the o/c. I can't find any cuts in the cable. That is what I first suspected. Is there another way that heat tape can fail?

Top
#101941 - 03/06/04 07:36 AM Re: heat tape
CRM Offline
Member

Registered: 02/29/04
Posts: 73
Loc: Alberta Canada
Is it tripping on overload or short circuit. I would measure how much current the heat tape is drawing. Somebody may have double lugged the breaker to feed another load, and now your drawing to much current.

Top
#101942 - 03/06/04 05:14 PM Re: heat tape
crash Offline
Member

Registered: 10/21/03
Posts: 130
Loc: Calgary Canada
My first guess would have been a defective GFCI. My second guess would have been a fault to ground. But those posibilities have been ruled out.

The last system I installed had a small control module (to measure temperature and presence of water in the eaves troughing). The module was to be installed under the eave, I did not think the eave would provide very much protection from the weather, and the unit would probably evetually fail as a result. The other posibility is the tape is itself shorting out (maybe a break down of the insulation is causing this).

Top
#101943 - 03/11/04 08:04 PM Re: heat tape
twh Offline
Member

Registered: 03/11/04
Posts: 899
Loc: Regina, Sask.
Some self-regulating heat tapes draw more current when they are cold. I measured one at three times it's rated current. The current dropped to normal in about a minute - a long enough time to trip the breaker. Check the amps when you first reset the breaker.

[This message has been edited by twh (edited 03-12-2004).]

Top
#101944 - 03/12/04 09:40 PM Re: heat tape
bill woods Offline
Member

Registered: 11/21/01
Posts: 45
well i think i found the problems. one set of tapes had 120 and 240 tapes combined on the same system. the other set of tapes had water leaking into the contactor box. thank you everyone for the input.

Top


ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals